Where are you viewing your data when looking to see different color geopoints?
It is possible to symbolize your collected data based upon domain values when adding the feature service, which participates in your survey, to a web map in ArcGIS Online. The easiest way to do this is to go to the survey123.arcgis.com website > click on desired survey > Data > Open in Map Viewer. This will pull the feature service into a web map where you can "Style" and symbolize as desired.
Please let me know if this is what you were after.
if you want to symbolize the survey layer in the data tab of the Survey123 website:
Hi David. It looks like in your case, you are referring to the symbology of the survey data within the Survey123 field app (Sent, Draft, Inbox, Outbox folders). If that is the case, it is not possible to change the label size or symbology. If you are referring to the symbology of your survey data in the Data tab of the Survey123 website refer to this answer.